I think I was better than most kids at math, particularly algebra, but those kids grew up and caught up and I suspect many of them are as good or better at math than I am. I know nothing about child psychology or anything adjacent, but I honestly think a lot of "advanced child" stuff is just maturity.
ETA:
Should add that this carried on through high school, and since I finished my math two years early, I took college-level courses for math the last two years.
My mom would have none of that, and demanded I be put back in 4th grade.
And so I was, and it was like I wasn't gone for a single day. The class had not advanced at all.
This was quite unlike university, where I didn't dare miss a single lecture.